Unmanned Aerial Vehicles Crowd the Skies, A little-known but important milestone in modern warfare was reached in 2009: in that year the U.S. Air Force trained more operators of unmanned aerial vehicles (UAVs) than it did pilots. In an age when war is increasingly dominated by robots, the U.S. military alone fields at least 7,000 of these machines, which are either remotely guided by a human using a radio link or self-guided by preprogrammed flight plans. Interest in UAVs is global, however. More than 60 manufacturers in at least 40 countries are now servicing a market that is expected to exceed tens of billions of dollars over the next decade. It is not suprising, then, that Quentin Davies, the U.K.’s minister for defense equipment and support, predicted in July 2009 that the world is now witnessing the last generation of manned combat aircraft and that by 2030 UAVs will have displaced them.

A soldier from the U.S. 1st Infantry Division prepares an RQ-11 Raven miniature unmanned aerial …

Lui Jin—AFP/Getty Images

U.S. Marines monitor the flight of an unmanned aerial vehicle in remote southwestern Afghanistan in …

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A Growing Technology

UAVs, also called remotely piloted vehicles (RPVs) or unmanned aircraft systems (UASs), are aircraft without a pilot onboard. Fixed-wing UAVs resemble “smart weapons” such as cruise missiles, but they are superior because they return to their base after a mission and can be reused. Also, UAVs have two decisive advantages over manned aircraft: their use does not risk the lives of aircrews, and they can loiter over areas of interest longer than most types of aircraft with human pilots. The current generation of UAVs varies in size from small propeller-driven hand-launched models such as the German army’s Aladin to jet-powered intercontinental-range craft such as the U.S. Air Force’s RQ-4 Global Hawk. Prices range from a few hundred thousand dollars for small models to well over $100 million for a Global Hawk.

UAVs first took to the skies during World War II with radio-controlled target drones, and they continued to develop slowly through the Vietnam era, when film cameras were mounted onto jet-powered drones for photoreconnaissance missions. Truly modern UAVs did not begin to appear over battlefields until the 1980s, when a number of technical advancements made them much more effective. Advanced composite materials made for lighter, stronger airframes, and improved electronics permitted the development of high-resolution TV and infrared cameras. Also, full implementation of the Global Positioning System (GPS) in the 1990s made it possible to navigate UAVs with a precision that was previously unattainable.

UAVs began to garner media attention during NATO’s intervention in the Yugoslav civil war of the 1990s. In 1995 the U.S. Air Force put the RQ-1 Predator into service for airborne surveillance and target acquisition. With its pusher propeller driven by a four-cylinder gasoline engine, the Predator could cruise at 140 km/h (87 mph), stay aloft for up to 16 hours, and reach altitudes of 7,600 m (25,000 ft). Predators flying over Yugoslavia tracked troop movements, monitored refugees, and marked targets so that manned aircraft could attack them with laser-guided bombs.

A U.S. Air Force MQ-1 Predator unmanned aerial vehicle prepares to land at Balad Air Base, Iraq, …

Senior Airman Olufemi A. Owolbabi—U.S. Air Force/AP

The Predator remains the most widely used battlefield UAV operated by the United States. The entire system consists of the vehicle itself (with built-in radar, TV and infrared cameras, and laser designator), a ground-control station, and a communication suite to link the two by satellite. Though pilotless, the Predator is operated by approximately 55 personnel, including a pilot operator and a sensor operator as well as intelligence, maintenance, and launch and recovery specialists. The current version, designated the MQ-1, went into service in 2001 armed with two laser-guided AGM-114 Hellfire missiles, giving the UAV the ability to attack targets as well as identify them. The first time a Predator made a confirmed kill was in Yemen in 2002, when one operated by the CIA destroyed a vehicle carrying six members of al-Qaeda. A turboprop-powered version of the Predator, called the MQ-9 Reaper, is significantly larger and has a greater payload. The Reaper has been operational since 2007 with U.S. forces and is also used by Britain’s Royal Air Force.

The pilot (left) and sensor operator (right) of a U.S. Air Force MQ-1 Predator unmanned aerial …

UAV technology may be sophisticated, but it is still in its infancy. By 2009 some 65 Predators (each costing $4 million) had crashed, including at least 3 in 2009. Thirty-six of the crashes were attributed to human error. Since UAVs are not yet completely autonomous, their operators must display great skill in judging distance and speed when landing, a task made more difficult by a slight delay in signal transmission between the UAV and the ground-control station. Moreover, there are occasional technical glitches, such as the one that occurred in September 2009 when a Reaper on a combat mission over Afghanistan could no longer be controlled and had to be shot down by U.S. warplanes.

Successful attacks by UAVs depend upon the accuracy and timeliness of intelligence. This principle was demonstrated in 2009 when an al-Qaeda military planner was believed to have been killed by an American UAV in September but suddenly appeared in a media interview in October. Also, high-tech weapons may win engagements on the battlefield, but they cannot solve political problems—and on occasion they may even aggravate them. In July 2009 the Brookings Institution think tank estimated that for every militant killed by a UAV in Afghanistan and Pakistan, approximately 10 civilians were also killed, a situation that was alienating the local population and turning them against the United States and its NATO allies. UAV use also raises issues of accountability. According to the nongovernmental organization Human Rights Watch, Israeli UAVs unlawfully killed at least 29 Palestinian civilians during the Gaza incursion in late 2008 and early 2009 because UAV operators allegedly failed to verify that targets were combatants.

Future Uses in War and Peace

Most UAVs remain dedicated to what the military calls ISTAR—intelligence, surveillance, target acquisition, and reconnaissance. For example, American UAVs began patrolling off the coast of Somalia in October 2009 in order to provide early warning of pirate vessels approaching merchant ships and to guide naval forces. However, the number of potential uses for UAVs is growing. In August 2009 the U.S. Marine Corps awarded contracts to Boeing and a joint venture between Lockheed Martin and Kaman to develop cargo UAVs that would be capable of delivering supplies to troops on the battlefield. The goal is to demonstrate how such UAVs could reduce risk and expense in logistics. Currently it is expensive to operate ground supply convoys on the poor roads and in the back country of Afghanistan; also, convoys must be heavily guarded, and they continually run risks from roadside bombs and ambushes.

Besides these military uses, UAV technology is attracting interest from police forces and other civilian agencies. For example, the U.S. Customs and Border Patrol has been using the Predator to patrol the Mexico-U.S. border since 2005 and the Canada-U.S. border since early 2009, and two maritime-patrol variants are scheduled to be operational in 2010. UAVs are also being developed for use in search-and-rescue operations to help locate survivors and deliver emergency supplies to them. In addition, UAVs are being evaluated for their potential in assessing damage suffered from disasters such as hurricanes, forest fires, and maritime oil spills.

As robotic vehicles become more commonplace, UAVs can be expected to be used wherever possible to minimize threats to personnel and to do tasks that exceed human strength and endurance. If current trends continue, UAVs could one day evacuate casualties from the heat of battle and mount round-the-clock surveillance missions for months and maybe even years at a time.